Britain's Foreign Secretary Phillip Hammond said there are five Britons confirmed dead and the Irish government said one of its citizens had been killed. Tunisia's government told CNN that the wounded include British nationals, three Belgians and one German.

Low-cost airline EasyJet(ESYJY) said passengers booked on flights to Tunisia could change their plans for free, or claim vouchers for future travel.

Thomas Cook, which operates hotels in the area, said customers could change their bookings free-of-charge for Tunisian holidays in June and July.

According to the firm's website, the Hotel Riu Imperial Marhaba is an all-inclusive five-star resort with 366 guest rooms.

Parent company TUI runs about 300 hotels in 24 countries. It employs 77,000 people and has businesses that include travel agencies, tour operators, airlines and cruise ships.

TUI is traded in London and Frankfurt and has a market capitalization of 9.3 billion euros ($10.4 billion).

In March, at least 23 people died when gunmen stormed the landmark Bardo Museum in Tunis. Until Friday, that attack had been the deadliest on tourists in the Arab world since a massacre in Luxor, Egypt, in 1997.